Switch to stestr

According to Openstack summit session [1],
stestr is maintained project to which all Openstack projects should migrate.
Let's switch to stestr as other projects have already moved to it.

[1] https://etherpad.openstack.org/p/YVR-python-pti

Change-Id: I739cd53efa4f685d721dc4c9095d5df273b2acae

.gitignore

@@ -28,7 +28,7 @@ pip-log.txt
 # Unit test / coverage reports
 .coverage
 .tox
-nosetests.xml
+.stestr/
 
 # Translations
 *.mo

.stestr.conf

@@ -0,0 +1,4 @@
+[DEFAULT]
+test_path=./mistraldashboard/tests
+top_dir=./
+

test-requirements.txt

@@ -11,6 +11,7 @@ mock>=2.0.0 # BSD
 nodeenv>=0.9.4 # BSD
 selenium>=2.50.1 # Apache-2.0
 xvfbwrapper>=0.1.3 #license: MIT
+stestr>=2.0.0 # Apache-2.0
 
 # Docs Requirements
 sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD

tox.ini

@@ -30,7 +30,13 @@ commands = {posargs}
 
 [testenv:cover]
 basepython = python3
-commands = python setup.py testr --coverage --testr-args='{posargs}'
+setenv =
+    PYTHON=coverage run --source mistraldashboard --parallel-mode
+commands =
+    stestr run '{posargs}'
+    coverage combine
+    coverage html -d cover
+    coverage xml -o cover/coverage.xml
 
 [testenv:docs]
 basepython = python3